The human brain is one of the most complex natural systems known. This is not simply because it has been relatively short time since technological development has allowed the creation of adequate measurement tools to study this set of organs, but because an average human brain of an adult contains approximately 80,000,000 neurons. The key is in how these nerve cells are connected.

As we will see in this article, the concept of conectoma was born to help us understand the internal logic of something as complicated as a brain.

What is the connector?

As we have seen, there are an overwhelming number of nerve cells in the human brain. But, in addition, each neuron is able to connect with hundreds, thousands of other neurons . These connections can change and develop over time.

It can be said that if our nervous system works it is because neurons are capable of sending millions of nerve impulses to each other through these contacts, called synapses. Each neuron, individually, is not capable of performing any of the functions that allow us to think, feel or even stay alive.

A connectoroma, then, is a mapping of the neural connections that exist in a nervous system or part of a nervous system , usually a brain. In recent years several projects have appeared through which an attempt is made to understand the functioning of various parts of the nervous system thanks to these representations.

Structural connections and functional connections

When designing connectors, it is possible to describe both structural and functional connections. The former reveal general and macro-anatomical patterns of connectivity , usually embodied in clustered axon bundles running from one part of the nervous system to another region of the system. The second shows focus on smaller details related to the likelihood of one group of neural connections sending certain nerve impulses to another group, a connection that is often more unpredictable and disrupted.

The Human Conectome Project

It is common to compare the concept of the conectome with that of the genome, a word which in turn refers to the information contained in another type of biological structure: DNA.
Just as in the 20th century biology and related scientific disciplines saw great hope in the possibility of unraveling the internal logic of the human genome, in recent years neuroscience and psychology, as well as the computer sciences , have begun to look at the possibility of understanding the typical conectome of the members of our species.

That is why in 2009 the Human Connectome Project was born, or Project Human Connectome, funded by members of the National Institutes of Health, United States of America. The link between this initiative and health is evident: it is possible to map the connections of a healthy human brain, but also of one associated with a particular mental illness , in order to locate significant differences in the way in which the nerve cells communicate with each other in each case.

It is reasonable to look for the causes of certain disorders in this pattern of connectivity, since there is currently an important consensus around the idea that mental processes are more likely to have functional problems if the groups of neurons that drive them are far apart from each other, since working with such distances involves assuming a higher metabolic cost. If in a brain that distance between groups of neurons is abnormally large, alterations in perception or behavior could appear. To date, the Human Connectome Project is still underway.

A picture of the brain?

As we have seen, the connectoroma is a kind of map of the brain, and its existence can facilitate the understanding of its functioning . However, by its very nature, it is a tool with limited power.

This is because the nervous system, especially the brain, is a constantly changing system. This is a phenomenon known as neuronal plasticity, by which any experience, regardless of its importance in psychological terms, causes the patterns of connectivity and activity of our neurons to change.

Thus, a connectoroma can give a rough idea of the functioning of certain behavioural logics, the effects of some mental diseases and brain injuries, and can even serve to create neural network learning systems in computers. In fact, there have already been promising achievements, such as recreating the brain connectoroma of a type of worm, creating a simulation with it, and making it learn certain behaviours just as one of these animals would do without programming a single line of code.

But a connector cannot accurately predict the behavior of an organism with a brain like the human one or one of similar complexity, since it is constantly changing. If we are able to reach that level of knowledge, it seems that there is still a long way to go.